Gaspard U J, Dubois M, Gillain D, Franchimont P, Duvivier J
Contraception. 1984 Apr;29(4):305-18. doi: 10.1016/0010-7824(84)90064-7.
For various metabolic and clinical reasons, it has been strongly advocated to reduce the dose of both the estrogen and progestogen components of oral contraceptives (OCs). In this study, we compared after 6 months of treatment, the action on various hormonal parameters of a standard-dose combined OC containing ethinylestradiol (EE) 0.050 mg and levonorgestrel (LNg) 0.250 mg and a low-dose triphasic combination containing a 59% reduced amount of the same steroids. Hormonal measurements in the last 3 days of OC intake indicated that basal levels of FSH and LH were less inhibited by the low-dose preparation, while PRL levels were unchanged. However, gonadal function was effectively inhibited by both high and low dose OCs, as demonstrated by equally low levels of E2, E1, P and 17-P. Consequently, no residual gonadal function could be anticipated from the observed low steroid concentrations. These results corroborated other studies (reviewed in this paper) in which serial hormonal measurements also revealed a complete lack of follicular maturation during low-dose triphasic OC treatment. Moreover, inhibition of circulating levels of A, DHEA, DHEAS, free T and DHT was similarly obtained with both preparations. Collectively, these data indicate that ovarian function is as effectively inhibited by a low-dose triphasic preparation as by a higher, standard-dose OC containing the same steroids.
由于各种代谢和临床原因，强烈主张降低口服避孕药（OCs）中雌激素和孕激素成分的剂量。在本研究中，我们比较了治疗6个月后，含0.050mg炔雌醇（EE）和0.250mg左炔诺孕酮（LNg）的标准剂量复方OC与含相同甾体激素量减少59%的低剂量三相复方OC对各种激素参数的作用。在服用OC的最后3天进行的激素测量表明，低剂量制剂对FSH和LH基础水平的抑制作用较小，而PRL水平未发生变化。然而，高剂量和低剂量OCs均有效抑制了性腺功能，E2、E1、P和17-P水平同样较低即证明了这一点。因此，从观察到的低甾体激素浓度来看，无法预期存在残余性腺功能。这些结果证实了其他研究（本文对此进行了综述），其中系列激素测量也显示在低剂量三相OC治疗期间完全缺乏卵泡成熟。此外，两种制剂对A、DHEA、DHEAS、游离T和DHT循环水平的抑制作用相似。总体而言，这些数据表明，低剂量三相制剂对卵巢功能的抑制作用与含相同甾体激素的高剂量标准OC一样有效。
